S12XE BDM Communication Loss

Hi. I have a new board which uses MC9S12XEQ512. I can program the board any number of times without any problems. But when I start the code, after some unspecified time, my Multilink Interface seems to lose communication with the MCU, and all variables read "0" (zero). The board keeps running, I can interact with it (external world), but without any debug info.

If I try to HALT, nothing happens (maybe because it's a command), and I can only RESET the board. Then it starts ok, and after some time it all happens again.

Have you tried measuring the reset pin? Because the MCU is disconnected from the debugger when a reset occurs. You may also try to connect the debugger to the MCU (while it is running) through Hotsync instead of Connect(Reset).